unzip: change license to info-zip

We have this license in our license list no reason not to use

pkgs/tools/archivers/unzip/default.nix

···
   meta = {
     homepage = "http://www.info-zip.org";
     description = "An extraction utility for archives compressed in .zip format";
-    license = lib.licenses.free; # http://www.info-zip.org/license.html
+    license = lib.licenses.info-zip;
     platforms = lib.platforms.all;
     mainProgram = "unzip";
   };